#include <iostream>
+#include "search.h"
#include "thread.h"
#include "ucioption.h"
namespace { extern "C" {
// start_routine() is the C function which is called when a new thread
- // is launched. It simply calls idle_loop() of the supplied thread.
- // There are two versions of this function; one for POSIX threads and
- // one for Windows threads.
+ // is launched. It simply calls idle_loop() of the supplied thread. The
+ // last two threads are dedicated to read input from GUI and to mimic a
+ // timer, so they run in listener_loop() and timer_loop() respectively.
#if defined(_MSC_VER)
-
DWORD WINAPI start_routine(LPVOID thread) {
-
- ((Thread*)thread)->idle_loop(NULL);
- return 0;
- }
-
#else
-
void* start_routine(void* thread) {
+#endif
- ((Thread*)thread)->idle_loop(NULL);
- return NULL;
- }
+ if (((Thread*)thread)->threadID == 0)
+ ((Thread*)thread)->main_loop();
-#endif
+ else if (((Thread*)thread)->threadID == MAX_THREADS)
+ ((Thread*)thread)->timer_loop();
+ else
+ ((Thread*)thread)->idle_loop(NULL);
+
+ return 0;
+ }
} }
activeThreads = cnt;
- for (int i = 0; i < MAX_THREADS; i++)
+ for (int i = 1; i < MAX_THREADS; i++) // Ignore main thread
if (i < activeThreads)
{
// Dynamically allocate pawn and material hash tables according to the
void ThreadsManager::init() {
+ // Initialize sleep condition used to block waiting for end of searching
+ cond_init(&sleepCond);
+
// Initialize threads lock, used when allocating slaves during splitting
lock_init(&threadsLock);
// Initialize sleep and split point locks
- for (int i = 0; i < MAX_THREADS; i++)
+ for (int i = 0; i <= MAX_THREADS; i++)
{
lock_init(&threads[i].sleepLock);
cond_init(&threads[i].sleepCond);
}
// Initialize main thread's associated data
- threads[0].is_searching = true;
- threads[0].threadID = 0;
- set_size(1); // This makes all the threads but the main to go to sleep
+ threads[0].pawnTable.init();
+ threads[0].materialTable.init();
- // Create and launch all the threads but the main that is already running,
- // threads will go immediately to sleep.
- for (int i = 1; i < MAX_THREADS; i++)
+ // Create and launch all the threads, threads will go immediately to sleep
+ for (int i = 0; i <= MAX_THREADS; i++)
{
threads[i].is_searching = false;
+ threads[i].do_sleep = true;
threads[i].threadID = i;
#if defined(_MSC_VER)
void ThreadsManager::exit() {
- // Wake up all the slave threads at once. This is faster than "wake and wait"
- // for each thread and avoids a rare crash once every 10K games under Linux.
- for (int i = 1; i < MAX_THREADS; i++)
+ for (int i = 0; i <= MAX_THREADS; i++)
{
threads[i].do_terminate = true;
threads[i].wake_up();
- }
- for (int i = 0; i < MAX_THREADS; i++)
- {
- if (i != 0)
- {
- // Wait for slave termination
+ // Wait for slave termination
#if defined(_MSC_VER)
- WaitForSingleObject(threads[i].handle, 0);
- CloseHandle(threads[i].handle);
+ WaitForSingleObject(threads[i].handle, 0);
+ CloseHandle(threads[i].handle);
#else
- pthread_join(threads[i].handle, NULL);
+ pthread_join(threads[i].handle, NULL);
#endif
- }
// Now we can safely destroy locks and wait conditions
lock_destroy(&threads[i].sleepLock);
}
lock_destroy(&threadsLock);
+ cond_destroy(&sleepCond);
}
}
+// split_point_finished() checks if all the slave threads of a given split
+// point have finished searching.
+
+bool ThreadsManager::split_point_finished(SplitPoint* sp) const {
+
+ for (int i = 0; i < activeThreads; i++)
+ if (sp->is_slave[i])
+ return false;
+
+ return true;
+}
+
+
// split() does the actual work of distributing the work at a node between
// several available threads. If it does not succeed in splitting the
// node (because no idle threads are available, or because we have no unused
// Explicit template instantiations
template Value ThreadsManager::split<false>(Position&, SearchStack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
template Value ThreadsManager::split<true>(Position&, SearchStack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
+
+
+// Thread::timer_loop() is where the timer thread waits maxPly milliseconds
+// and then calls do_timer_event().
+
+void Thread::timer_loop() {
+
+ while (!do_terminate)
+ {
+ lock_grab(&sleepLock);
+ timed_wait(&sleepCond, &sleepLock, maxPly ? maxPly : INT_MAX);
+ lock_release(&sleepLock);
+ do_timer_event();
+ }
+}
+
+
+// ThreadsManager::set_timer() is used to set the timer to trigger after msec
+// milliseconds. If msec is 0 then timer is stopped.
+
+void ThreadsManager::set_timer(int msec) {
+
+ Thread& timer = threads[MAX_THREADS];
+
+ lock_grab(&timer.sleepLock);
+ timer.maxPly = msec;
+ cond_signal(&timer.sleepCond); // Wake up and restart the timer
+ lock_release(&timer.sleepLock);
+}
+
+
+// Thread::main_loop() is where the main thread is parked waiting to be started
+// when there is a new search. Main thread will launch all the slave threads.
+
+void Thread::main_loop() {
+
+ while (true)
+ {
+ lock_grab(&sleepLock);
+
+ do_sleep = true; // Always return to sleep after a search
+
+ is_searching = false;
+
+ while (do_sleep && !do_terminate)
+ {
+ cond_signal(&Threads.sleepCond); // Wake up UI thread if needed
+ cond_wait(&sleepCond, &sleepLock);
+ }
+
+ is_searching = true;
+
+ lock_release(&sleepLock);
+
+ if (do_terminate)
+ return;
+
+ Search::think();
+ }
+}
+
+
+// ThreadsManager::start_thinking() is used by UI thread to wake up the main
+// thread parked in main_loop() and starting a new search. If asyncMode is true
+// then function returns immediately, otherwise caller is blocked waiting for
+// the search to finish.
+
+void ThreadsManager::start_thinking(const Position& pos, const Search::LimitsType& limits,
+ const std::vector<Move>& searchMoves, bool asyncMode) {
+ Thread& main = threads[0];
+
+ lock_grab(&main.sleepLock);
+
+ // Wait main thread has finished before to launch a new search
+ while (!main.do_sleep)
+ cond_wait(&sleepCond, &main.sleepLock);
+
+ // Copy input arguments to Search global variables
+ Search::RootPosition.copy(pos, 0);
+ Search::Limits = limits;
+ Search::RootMoves = searchMoves;
+
+ // Reset signals before to start the search
+ memset((void*)&Search::Signals, 0, sizeof(Search::Signals));
+
+ main.do_sleep = false;
+ cond_signal(&main.sleepCond); // Wake up main thread
+
+ if (!asyncMode)
+ cond_wait(&sleepCond, &main.sleepLock);
+
+ lock_release(&main.sleepLock);
+}
+
+
+// ThreadsManager::wait_for_stop_or_ponderhit() is called when the maximum depth
+// is reached while the program is pondering. The point is to work around a wrinkle
+// in the UCI protocol: When pondering, the engine is not allowed to give a
+// "bestmove" before the GUI sends it a "stop" or "ponderhit" command.
+// We simply wait here until one of these commands (that raise StopRequest) is
+// sent, and return, after which the bestmove and pondermove will be printed.
+
+void ThreadsManager::wait_for_stop_or_ponderhit() {
+
+ Search::Signals.stopOnPonderhit = true;
+
+ Thread& main = threads[0];
+
+ lock_grab(&main.sleepLock);
+
+ while (!Search::Signals.stop)
+ cond_wait(&main.sleepCond, &main.sleepLock);
+
+ lock_release(&main.sleepLock);
+}